The package addressed to chief inspector Andy Lemon, was intercepted at a sorting office in Strabane, Co. Tyrone, BreakingNews.ie.

The alarm was raised after postal workers at an office on Castle Street discovered a suspicious package. A spokesman for the Police Service of Northern Ireland (PSNI) said it was a small viable device.

He said “It has been taken away for further examination.”

Bomb squad officers carried out their investigations during a security operation which resulted in six roads around the sorting office being closed for several hours.

Mr Lemon is the area commander in Strabane and the most senior officer to be targeted with a bomb in two decades. He described the situation as a worrying development and claimed that the postal staff saved lives.

“It could have gone up at any time, this was a very dangerous device and I would like to praise the Post Office staff for noticing it. One of them, or one of my officers, could have been injured had they opened it,” he said.

The device, which has been described as crude, was made up of a battery pack and accelerant. It was packed into a brown envelope and addressed to Mr Lemon at Strabane police station.

He added: “I do not believe this is a personal attack but more a general attack on the police. Because I am area commander, a lot of mail would come into the police station addressed to myself, but I do not open any of it. That is done by other members of staff.

“This was an attempt to kill or injure police.”

Mr Lemon said despite the threat PSNI officers would not be deterred from their duty.

“We have a job to do. The threat is severe, it has been severe for some time. We deal with it daily and do as much as we can to try and minimise that threat,” he explains.

He said the PSNI were keeping an open mind about who was responsible but acknowledged that dissident republicans were the most likely suspects.

Sinn Fein MLA for Strabane, Michaela Boyle said lives were put at risk.

She said: “What is to be gained by this? This has put the lives of postal workers at risk as well as others. It caused mayhem and disruption to the town and wider community.

“It is a Friday and we have a market in the town which generates a lot of people from other places coming into the town. A lot of revenue has been lost by businessmen and women who are already struggling.

“There is no place in society for this sort of activity from these individuals. It could have been fatal.”

Brian Rea, chairman of the Northern Ireland policing board said: “Whilst this has been described as a small device it had the potential to cause injury. Whoever sent this package really didn’t care about the harm it could have caused and I praise the vigilance of the postal workers in spotting it.”

DUP MLA Ross Hussey, who sits on the Policing Board added his condemnation.

“It is quite clear that so-called dissident republicans are oblivious to the pleas from across the political spectrum that they cease their activities and leave the rest of society to live in peace. The Police are here to serve and protect the entire community and an attack on one police officer is an attack on all of us,” he said.

The North’s First and Deputy First Ministers described the attack as calculated and callous and have appealed to its residents to help police identify those responsible.

In a joint statement Peter Robinson and Martin McGuinness said: “The individuals behind this need to be brought to justice as actions like this have no place in society and those responsible have nothing positive to offer. This was not just a planned attack on a police officer but also on the postal workers involved and society as a whole.

“Violence plays no part in our future. We would appeal to anyone with any information on this to contact the PSNI.”